如果pod undate 的时候报错"undefined method `root' for nil:NilClass" error when using "pod install" 或
NoMethodError - undefined method `dirname' for nil:NilClass
检查你的podfile文件 保证一下信息存在
Pod::Spec.new do |s|
s.name = "DDEBusiness"
s.version = "0.0.1"
s.platform = :ios, "7.0"
s.authors = "dingdone"
s.license = "dingdone"
s.homepage = "http://www.dingdone.com"
s.summary = "dingdone"
s.source = { :git => "http://git.hoge.cn/dingdone_ios_spec/DDEBusiness.git", :tag => "0.0.1" }